title: A new TCM formula FTZ lowers serum cholesterol by regulating HMG-CoA reductase and CYP7A1 in hyperlipidemic rats.
abstract: BACKGROUND
  Based on a theory of Chinese Medicine, Regulating Gan (liver) to lower lipids that is in brief to regulate the lipid metabolic related factors in the liver will improve serum lipid profile, we have developed Fufang Zhenzhu Tiao Zhi (FTZ) which includes eight herbs that are quality assured. FTZ has been developed with the potential to correct abnormal lipid metabolism. This Chinese herbal medicine has been prescribed for 20 years, which has been issued patent and clinically proven for use in the treatment of dyslipidemia.
  
  
  OBJECTIVE
  To investigate the cholesterol-lowering effect and the mode of action of FTZ extract on high lipid diet induced hyperlipidemic rats.
  
  
  METHODS
  The FTZ was prepared by alcohol and water extraction of eight herbs that have been quality-controlled according to the protocol. The cholesterol-lowering effect of FTZ was evaluated on SD rats fed with high-lipid diet. RT-PCR and western blot were used to analyze the gene expression of cholesterol metabolism-related enzymes including HMG-CoA reductase and cholesterol 7α-hydroxylase (CYP7A1) in the livers of the rats. The activity of HMG-CoA reductase and CYP7A1 were assessed by colorimetrical method and by quantification of the cholesterol metabolite of CYP7A1 using HPLC analysis respectively.
  
  
  CONCLUSIONS
  FTZ significantly decreased the levels of serum total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C), whilst elevated the serum high-density lipoprotein cholesterol (HDL-C) and decreased serum atherogenic index (A.I.) values in high lipid diet induced hyperlipidemic rats. Furthermore, FTZ showed significant antihyperlipidemic effect by at least three pathways in the high lipid diet induced hyperlipidemic rats: (1) upregulating the gene expression and activity of CYP7A1 which promotes the conversion of cholesterol into bile acid; (2) downregulating the gene expression and activity of HMG-CoA reductase to reduce de novo synthesis of cholesterol; (3) increasing the cholesterol excretion from feces. In these three pathways, HMG-CoA reductase and CYP7A1 are two pivotal enzymes in lipid cholesterol metabolism and are expressed mainly in hepatic cells, which support our new TCM treatment strategy: Modulating Liver to Treat Hyperlipemia.
authors.affiliation: Institute of Chinese Medicinal Sciences, Guangdong Pharmaceutical University, Guangzhou University of Chinese Medicine, Guangzhou Higher Education Mega Centre, Guangzhou 510006, PR China. 806362747@139.com
authors.forename: Jiao
authors.initials: J
authors.lastname: Guo
authors.forename: Weijian
authors.initials: W
authors.lastname: Bei
authors.forename: Yinming
authors.initials: Y
authors.lastname: Hu
authors.forename: Chunping
authors.initials: C
authors.lastname: Tang
authors.forename: Wei
authors.initials: W
authors.lastname: He
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Liu
authors.forename: Lihua
authors.initials: L
authors.lastname: Huang
authors.forename: Yang
authors.initials: Y
authors.lastname: Cao
authors.forename: Xuguang
authors.initials: X
authors.lastname: Hu
authors.forename: Xunlong
authors.initials: X
authors.lastname: Zhong
authors.forename: Le
authors.initials: L
authors.lastname: Cao
mesh_terms: D000818:Animals; D000924:Anticholesteremic Agents / Q000627:therapeutic use*; D001483:Base Sequence; D015153:Blotting, Western; D002784:Cholesterol / Q000097:blood*; D002790:Cholesterol 7-alpha-Hydroxylase / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D017931:DNA Primers; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use*; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000924:Anticholesteremic Agents; D017931:DNA Primers; D004365:Drugs, Chinese Herbal; D002784:Cholesterol; D006903:Hydroxymethylglutaryl CoA Reductases; C553219:CYP7A1 protein, human; D002790:Cholesterol 7-alpha-Hydroxylase